Dual air admittance valve

ABSTRACT

Embodiments of a valve assembly and a plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly for use with an enclosed environment includes a housing having an interior volume, an inlet disposed at a first end of the housing and fluidly coupled to an environment surrounding the housing, and an outlet disposed at a second end of the housing opposite the first end and fluidly coupled to the enclosed environment; a first valve having a first valve seat and a first sealing member at least partially extending through a first opening in the first valve seat in a closed position; and a second valve disposed beneath the first valve and having a second valve seat and a second sealing member at least partially extending through a second opening in the second valve seat in a closed position.

CROSS-REFERENCE RELATED TO RELATED APPLICATIONS

This application is a continuation of U.S. Nonprovisional applicationSer. No. 15/374,099, filed Dec. 9, 2016, now U.S. Pat. No. 10,253,485,which is a continuation-in-part of commonly-owned, same inventor,presently co-pending U.S. Nonprovisional patent application Ser. No.15/299,446, filed Oct. 20, 2016, now abandoned, which is acontinuation-in-part of U.S. Nonprovisional patent application Ser. No.15/293,315, filed Oct. 14, 2016, now U.S. Pat. No. 9,657,468, which is acontinuation-in-part of U.S. Nonprovisional patent application Ser. No.15/275,419, filed Sep. 25, 2016, now U.S. Pat. No. 10,030,372, which isa continuation-in-part of U.S. Nonprovisional patent application Ser.No. 15/246,464, filed Aug. 24, 2016, now U.S. Pat. No. 9,926,691, whichis a continuation-in-part of U.S. Nonprovisional patent application Ser.No. 15/132,131, filed Apr. 18, 2016, now U.S. Pat. No. 9,797,120, whichclaims the priority and benefit of U.S. Provisional Application No.62/151,463, filed Apr. 23, 2015, all of which are incorporated in theirentirety herein by reference.

FIELD OF THE INVENTION

This invention generally relates to valves and more specifically, tovalve assemblies for use in enclosed systems through which a mediumflows or is stored.

BACKGROUND

A variety of air admittance valves and check valves have been developedfor allowing air to enter a piping system or an enclosed environmentunder a negative or vacuum pressure, which is created when water flowsdown the drain, to prevent siphoning of traps or when a sump pump pumpswater and air out of an enclosed sump pit. Attaching an air admittancevalve or check valve allows ambient air to enter the enclosedenvironment to eliminate the negative pressure or vacuum in the enclosedsystem. Many of these valves are specifically designed for systems suchas piping systems and sewer systems where it is difficult or impossibleto install a local vent or air intake due to the difficulty of runningpipes through an existing building. Typically, these air admittance orcheck valves only provide specific operating conditions such as, forexample, the vacuum pressure in the amount of air required. Conventionalair admittance and check valves available do not provide forinstantaneous and higher volume of air demand, which is undesirable whenexisting air admittance components are installed on systems requiringthe higher airflow demand because the higher airflow demand causesstrain on the air admittance component and causes it to fail prematurelysince the air admittance component was designed to function based on anatural gravity air flow vacuum or negative pressure constraint.Additionally, conventional air admittance components do not filter theair and therefore can allow for corrosive elements to pass through tothe enclosed system, thus damaging the air admittance components and,potentially, the entire system.

In addition, an undesirable scenario is encountered when a negativepressure is generated in the piping system when flow is drained from thepiping system. When such a negative pressure occurs, the water seals inthe U-band or trap of the piping system will be syphoned out and can,therefore, no longer prevent sewer gas from entering the building. Toaddress this issue, conventional air admittance and check valves havebeen designed to allow air to enter the piping system to prevent thenegative pressure scenario. However, as explained above, conventionalair admittance and check valves fail easily.

As such, there is currently no product available for a higher volumedemand in a negative pressure scenario such as an enclosed pit with apump requiring air to enter the system at the same rate at which wateris pumped out. For example, a pump that pumps out 20 gallons of waterper minute and would require a large demand of airflow to enter thesystem so that a vacuum is not formed in the enclosed environmentresulting in stress on the pump and causing improper water discharge. Inthe case of a sump pump, the pump becomes air-locked and runscontinuously, which causes the pump to overheat, burn out and/or failresulting in flooding of the area and water damage to the building.

In many cases, a proper seal is required to provide a water and airtightseal after air has been allowed to enter the system and the pumpdisengages. Furthermore, if such an air admittance component does fail,the failure should occur in a closed/sealed position of the component toprovide continued protection so that no fluid or gas can escape into thesurrounding environment within the building or within a given heightabove the building's roof.

Although some check valves include a ball inside the valve to block orallow air flow through the valve, these conventional ball valves tend tofouled, which prevents the ball from achieving a perfect seal andblocking the air flow properly. A further drawback of conventional ballvalves is the little to no rotation of the ball, resulting in wear ofthe ball from sealing at the same location.

A further drawback with conventional check valves is the lack of afailsafe in case a valve failure occurs. In other words, whenconventional check valves fail, they cease to operate for their intendedpurpose. As such, two check valves are often installed in series, whichis undesirable because this practice involves additional branch-offs andadditional labor.

Therefore, the inventor has developed an improved valve assembly for usewith an enclosed volume that needs to be vented.

SUMMARY OF THE INVENTION

Embodiments of a valve assembly and a plumbing system incorporating thesame are provided herein. In some embodiments, a valve assembly for usewith an enclosed environment, comprising: a housing having an interiorvolume, an inlet disposed at a first end of the housing and fluidlycoupled to an environment surrounding the housing, and an outletdisposed at a second end of the housing opposite the first end andfluidly coupled to the enclosed environment; a first valve having afirst valve seat and a first sealing member at least partially extendingthrough a first opening in the first valve seat in a closed position,wherein the first sealing member is moveable between an open positionwhich allows air to pass through the first opening and a closed positionin which the first sealing member blocks air from moving through thefirst opening; a second valve disposed beneath the first valve andhaving a second valve seat and a second sealing member at leastpartially extending through a second opening in the second valve seat ina closed position, wherein the second sealing member is moveable betweenan open position which allows air to pass through the second opening anda closed position in which the second sealing member blocks air frommoving through the second opening; a first filter element disposed at orproximate to the inlet and having a first plurality of openingsconfigured to prevent any object having a size larger than any one ofthe first plurality of openings from passing through the first filterelement into the interior volume; and a second filter element disposedat or proximate to the inlet and having a second plurality of openingsconfigured to prevent any object having a size larger than any one ofthe second plurality of openings from passing through the second filterelement into the interior volume, wherein the first valve seat isdisposed in an upper portion of the interior volume and the second valveseat is disposed in a lower portion of the interior volume, and whereinthe first and second valve seats divide the interior volume into a firstzone, a second zone, and a third zone.

In some embodiments, a valve assembly for use with an enclosedenvironment a housing having an interior volume and an inlet disposed ata first end of the housing and fluidly coupled to an environmentsurrounding the housing, wherein the interior volume is defined by awall and a ceiling of the housing, wherein the ceiling is disposed at asecond end of the housing opposite the first end; a pipe extending intothe interior volume and having an end disposed below the ceiling of thehousing, wherein the end of the pipe has an inlet opening fluidlycoupled to the enclosed environment; a first valve having a first valveseat and a first sealing member disposed above the first valve seat,wherein the first valve seat includes a first seat outer ring coupled tothe wall of the housing and a first seat inner ring coupled to anexterior wall of the pipe, wherein the first sealing member includes afirst central opening through which the pipe extends, and wherein thefirst sealing member is moveable between an open position in which airis allowed to pass through a first space between the first seat outerand inner rings and a closed position in which air is prevented frommoving through the first space; a second valve disposed beneath thefirst valve and having a second valve seat and a second sealing memberdisposed above the second valve seat, wherein the second valve seatincludes a second seat outer ring coupled to the wall of the housing anda second seat inner ring coupled to the exterior wall of the pipe,wherein the second sealing member includes a second central openingthrough which the pipe extends, and wherein the second sealing member ismoveable between an open position in which air is allowed to passthrough a second space between the second seat outer and inner rings anda closed position in which air is prevented from moving through thesecond space; an annular filter element disposed at or proximate to theinlet and configured to prevent contaminants from passing through theannular filter element into the interior volume; and a second filterelement disposed within the pipe at or proximate to the inlet openingand configured to prevent contaminants from passing through the secondfilter element into the pipe, wherein at least one of the first valve orsecond valve includes a flexible membrane section disposed in the firstor second sealing member and a ring disposed atop the flexible membranesection, wherein the ring has a predetermined weight and is configuredto bias the first or second sealing member towards the closed position,wherein the first valve seat is disposed in an upper portion of theinterior volume and the second valve seat is disposed in a lower portionof the interior volume, and wherein the first and second valve seatsdivide the interior volume into a first zone, a second zone, and a thirdzone.

BRIEF DESCRIPTION OF THE DRAWINGS

It should be noted that the drawings are merely representative, are notnecessarily drawn to scale, and are not intended to limit the scope ofthe present invention.

FIG. 1 is a perspective view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 1A is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 1B is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 2 is a perspective view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 2A is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 2B is a cross-sectional view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 2C is a cross-sectional view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 3 is a perspective view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 3A is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 3B is a cross-sectional view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 3C is a cross-sectional view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 4 is a perspective view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 4A is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 4B is a cross-sectional view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 5 is a perspective view of a sealing member of a valve assembly inaccordance with some embodiments of the present invention.

FIG. 6 is a perspective view of a sealing member of a valve assembly inaccordance with some embodiments of the present invention.

FIG. 7 is a perspective view of a sealing member of a valve assembly inaccordance with some embodiments of the present invention.

FIG. 8 is a perspective view of a sealing member of a valve assembly inaccordance with some embodiments of the present invention.

FIG. 9 is a perspective view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 9A is a cross-sectional view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 10 is a perspective view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 10A is a cross-sectional view of a valve assembly in accordancewith some embodiments of the present invention.

FIG. 11 is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 12 is a schematic cross-sectional view of a valve assembly inaccordance with some embodiments of the present invention.

FIG. 12A is a perspective bottom view of a sealing member for use with avalve assembly in accordance with some embodiments of the presentinvention.

FIG. 12B is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 13 is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 14 is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 14A is a perspective view of a sealing member in accordance withsome embodiments of the present invention.

FIG. 15 is a perspective view of a valve assembly in accordance withsome embodiments of the present invention.

FIG. 16 is a cutaway view of a valve assembly in accordance with someembodiments of the present invention.

FIG. 16A is a perspective view of a sealing member for use with a valveassembly in accordance with some embodiments of the present invention.

FIG. 17 is a schematic view of an enclosed environment incorporating avalve assembly in accordance with some embodiments of the presentinvention.

FIG. 18 is a schematic view of an enclosed environment incorporating avalve assembly in accordance with some embodiments of the presentinvention.

FIG. 19 is a schematic view of a plumbing system incorporating a valveassembly in accordance with some embodiments of the present invention.

FIG. 20 is a schematic view of a plumbing system incorporating a valveassembly in accordance with some embodiments of the present invention.

FIG. 21 is a cross-sectional view of a conduit coupled to an enclosedenvironment and a valve assembly in accordance with some embodiments ofthe present invention.

FIG. 22 is a cutaway view of a valve assembly having a pressureindicator in accordance with some embodiments of the present invention.

FIGS. 23A and 23B are perspective views of a pressure indicator inaccordance with some embodiments of the present invention.

DETAILED DESCRIPTION

Embodiments of a valve assembly for use with an enclosed environment andsystems incorporating the same are disclosed herein. In someembodiments, the valve assembly may include a first valve and a secondvalve configured to be coupled to an enclosed environment, in which anegative pressure (i.e., a vacuum) is undesirable, to allow ambient airinto the enclosed environment, thus advantageously increasing thenegative pressure in the enclosed environment. For example, in someembodiments, the valve assembly may be coupled to a pipeline that iscoupled to the trap of a drainage system. When a negative pressureexists in the pipeline downstream of the trap, the seal provided bywater in the trap against sewage gas (e.g., methane), is broken, thusallowing the sewage gas to flow up through the drain pipe and into thehouse. The two valves of the inventive valve assembly advantageouslyprovide a failsafe measure against valve failure. In other words, whenone of the two valves fails (i.e., does not properly seal), the othervalve still functions to prevent the a backflow of gases from theenclosed environment. A further advantage of the inventive valveassembly is that failure occurs in the closed position because thevalves are biased towards a closed position by gravity. As such, even ifvalve failure occurs, the amount of backflow is significantly less thana fully open valve. Yet another advantage of the inventive valveassembly is its ability to avoid fouling by ensuring that the valvesealing member rotates.

FIGS. 1, 1A, and 1B depict perspective and cutaway views of a valveassembly 10 in accordance with some embodiments of the presentinvention. In some embodiments, the valve assembly 10 includes a housing20 having an interior volume 65, an inlet 66 disposed at a first end ofthe housing 20, and an outlet 67 disposed at a second end of the housing20 opposite the first end. The inlet 66 is fluidly coupled to theenvironment surrounding the housing 20 to allow ambient air to enterinto the interior volume 65. The outlet 67 is fluidly coupled to anenclosed environment (e.g., a pump pit, a pipeline, etc.), in which anegative pressure (i.e., a vacuum) may exist. The housing 20 is formedof any material that does not corrode or rust from exposure to water.For example, the housing 20 may be formed of plastic, copper, brass,cast iron, steel, or other commonly used materials in the fieldplumbing.

In some embodiments, the valve assembly 10 may include a first valve 80,having a first valve seat 100 and a first sealing member (e.g., firstspherical body 82), and a second valve 115 disposed beneath the firstvalve 80 and having a second valve seat 110 and a second sealing member(e.g., second spherical body 116). The first and second spherical bodies82, 116 mate with first and second openings 106, 112 in the first andsecond valve seats 100, 110, respectively, to selectively provide a sealagainst the corresponding valve seats. In some embodiments, at least oneof the first and second spherical bodies 82, 116 is formed of a solidmaterial having an exterior pliable layer to improve sealing capabilityof the spherical body. In some embodiments, at least one of the firstand second spherical bodies 82, 116 may alternatively be hollow andfilled with an inert gas such as, for example, argon, so that the sizeof spherical body does not change with changes in the ambienttemperature. The constant size of the spherical body ensures that thevalve will provide a sufficient seal consistently.

The first valve seat 100 is coupled to an inner wall 22 of the housing20 in an upper portion of the interior volume 65. The second valve seat110 is coupled to the inner wall 22 in a lower portion of the interiorvolume 65. Together, the first and second valve seats 100, 110 dividethe interior volume into a first zone 40 disposed between the firstvalve seat 100 and the outlet 67, a second zone 45 disposed between thefirst and second valve seats 100, 110, and a third zone 60 disposedbetween the second valve seat 110 and the inlet 66.

The first and second spherical bodies 82, 116 are moveable between anopen position (shown in FIGS. 1-1B), in which air is allowed to passfrom the inlet 66, through the first, second, and third zones 40, 45,60, and through the outlet 67, and a closed position, in which air doesnot pass through the zones and out of the outlet 67. The movement ofeach sealing member between the open and closed positions occurs whenthe pressure beneath the sealing member is greater than the combinationof the pressure above the sealing member and the weight of the sealingmember. For example, the first spherical body 82 is moved up to an openposition when total downward forces exerted on the first spherical body82 by the weight of the first spherical body 82 and a first pressure P1in the first zone 40 are less than an upward force exerted on the firstspherical body 82 by a second pressure P2 in the second zone 45.Likewise, the second spherical body 116 is moved up to an open positionwhen the total downward forces exerted on the second spherical body 116by the weight of the second spherical body 116 and the second pressureP2 are less than an upward force exerted on the second spherical body116 by a third pressure P3 in the third zone 60. In this manner, therespective weights of the first and second spherical bodies 82, 116 arechosen so that the valve assembly 10 functions at predetermined pressuredifferentials. In some embodiments, each of the first and secondspherical bodies 82, 116 may weigh between about 0.01 oz to about 1 lb 1oz, depending on the application of the invention in different enclosedenvironment or piping systems operating at different pressures insidethe enclosed environment or piping system.

When a negative pressure is present in the enclosed environment, towhich the outlet 67 is fluidly coupled, the first pressure P1 becomesless than the second pressure P2, which is originally at or nearatmospheric pressure but becomes less than the third pressure P3 (i.e.,atmospheric pressure) after the first valve 80 is opened. As such, theflow 180 of ambient air through the valve assembly 10 is facilitated bythe pressure differential between the enclosed environment at the outlet67 and the surrounding environment at the inlet 66. Each sealing memberhas predetermined weight selected so that when a predetermined pressuredifferential at each valve is reached, the valve opens to allow air flow180 through the opening in the valve seat.

In some embodiments, the valve assembly 10 may further include a firstfilter element 120 disposed at or proximate to the inlet 66. The firstfilter element includes a plurality of first openings 122 formed throughthe first filter element 120 and configured to prevent any foreignobject/contaminant having a size larger than any one of the plurality offirst openings from passing through the first filter element 120 intothe interior volume 65, thus interfering with the seal between thesealing member and the valve seat. Similarly, a second filter element140 may be disposed at or proximate to the outlet 67 and have aplurality of second openings 142.

In some embodiments, at least one of the first and second valve seats100, 110 may include a compliant section 620/640, respectively, formedof a compliant/flexible material and directly adjacent to andsurrounding the opening (i.e., corresponding one of the first and secondopenings 106, 112, respectively) to further improve the seal between thefirst and/or second spherical bodies 82/116 and their correspondingvalve seats. In some embodiments, the compliant section 620/640 is athin-walled section surrounding the first and second openings 106, 112.In some embodiments, the entire valve seat may be formed of thecompliant material. In some embodiments, the valve seat mayalternatively include an outer rigid section formed of a rigid materialsurrounding the compliant section. The rigid section may be formed ofrigid materials such as, for example, plastic (e.g., PVC), a denserubber with a high shore hardness (e.g., above about 80 A), anon-corrosive metal, or the like. When the compliant section 620/640 hasa radial width greater than or equal to that of the rigid section (firstvalve 80 in FIGS. 2-2C) the compliant section may act as a diaphragm toadvantageously alleviate a positive pressure in an adjacent zone inexcess of a threshold pressure (e.g., a pressure at which the water sealin a trap is disturbed or destroyed) by expanding, thus temporarilyincreasing the volume of the adjacent zone. The compliant material canbe any material that does not corrode with exposure to water and thathas a Shore Hardness between about 20 A and about 50 A. For example, thecompliant material may be rubber, EPDM (Ethylene Propylene DieneMonomer), silicon, and combination thereof.

Referring to FIGS. 2-2C, in some embodiments, the valve assembly 10includes at least one valve that includes a compliant section having aradial width greater than a radial width of the rigid section, asdiscussed above. For example, as depicted in FIGS. 2-2C, the first valve80 includes a compliant section 620 disposed radially inward of a firstannular rigid section 101 to act as a diaphragm, as explained above. Thefirst opening 106 is formed in the first compliant section 620. Thesecond valve seat 110 of the second valve 115 includes is formedprimarily of a rigid material and includes a thin-walled compliantsection 640. However, in an alternate embodiment, the second valve seat110 may be formed similarly to the first valve seat 100 (i.e., a radialwidth of the second compliant section 640 is greater than a radial widthof a second annular rigid section surrounding the second compliantsection 640, as depicted in FIGS. 3-3C).

When the first spherical body 82 rests in the first opening 106 in thefirst compliant section 620, and thus providing a seal, the firstcompliant section 620 is deformed downwardly. The downward deformationof the first compliant section 620 increases the second pressure P2 inthe second zone 45 due to the compression of the volume of the secondzone 45 and the fact that the second valve 115 is sealed. The secondpressure P2 in the second zone 45 may advantageously be monitored (e.g.,using a pressure monitoring device coupled to the second zone 45) todetect the increase of pressure that results from the downwarddeformation of the first compliant section 620 to determine that no leakexists in the seals provided by the first spherical body 82 against thewalls of the first opening and by the second spherical body 116 againstthe walls of the second opening 112. If, however, the downwarddeformation of the first compliant section 620 does not effect acorresponding increase in pressure in the second zone 45, then the firstvalve 80 and/or the second valve 115 has not sealed properly and a leakexists at the valve(s) that has not sealed properly.

In some embodiments, and as depicted in FIGS. 2B and 2C, the thin-walledcompliant section 640 of the second valve 115 may be a collar 625 havinga central reduced diameter area into which the rigid portion of thesecond valve seat 110 extends to hold the collar 625 in place. Thecollar 625 includes a central opening corresponding to the secondopening 112, in which the second spherical body 116 sits in the closedposition depicted in FIG. 2C.

Although the above description with regards to FIGS. 2-2C details thefirst valve 80 having a first compliant section 620 having a radialwidth greater than a radial width of the first rigid section 101 and thesecond valve 115 having a thin-walled compliant section 640, the firstcompliant section 620 may alternatively be thin-walled and the secondcompliant section 640 may alternatively have a radial width greater thana radial width of the second rigid section 111, as noted above and asdepicted in FIGS. 3-3C.

In some embodiments, and as depicted in FIGS. 4-4B, both the first andsecond valves 80, 115 may include respective first and second compliantsections 620, 640 each having radial widths greater than the radialwidths of the corresponding first and second rigid sections 101, 111. Insuch an embodiment, the respective weights of the first and secondspherical bodies 82, 116 are chosen to achieve a predetermined relativepressure difference in the second zone 45. In other words, the secondpressure P2 in the second zone 45 may be varied depending the relativeamounts of deformation of the first and second compliant sections 620,640 when the respective first and second spherical bodies 82, 116 restatop the compliant sections.

When the deformation of the first compliant section 620 is greater thanthe deformation of the second compliant section 640, the second zone 45is compressed, resulting in an increase of the second pressure P2. Whenthe deformation of the second compliant section 640 is greater than thedeformation of the first compliant section 620, the second zone 45expands, resulting in a decrease of the second pressure P2. If first andsecond compliant sections 620, 640 deform equally, the second pressureP2 will not be increased or decreased. As noted above, the relativedeformations of the first and second compliant sections 620, 640 can bevaried by choosing the respective weights of the first and secondspherical bodies 82, 116 to achieve the desired pressure in the secondzone 45. Also, the magnitude of the deformations of the first and secondcompliant sections 620, 640 can be predetermined even if the first andsecond spherical bodies 82, 116 have the same weight by using compliantmaterials having different shore hardness values between about 20 A andabout 60 A, the lesser values resulting in more deformation. Examples ofsuitable materials for the compliant sections may include rubber,synthetic rubber, EPDM (Ethylene Propylene Diene Monomer), silicon, andcombination thereof. Examples of suitable materials for the rigidsections may include PVC (Polyvinyl chloride), metal, HDPE (High DensityPolyethylene), or the like.

Although the following description of FIGS. 5-8 will be made withrespect to the first spherical body 82, the following is also applicableto the second spherical body 116. FIG. 5 depicts a first spherical body82 for use in a valve assembly (e.g., valve assembly 10) in accordancewith some embodiments of the present disclosure. In some embodiments,two first guides 84 may be mounted to the spherical body 116 on oppositesides. The two first guides 84 are configured to be mounted in andmoveable along two corresponding first tracks which will be discussed ingreater detail below with regards to FIGS. 9-10A. The air flow 180facilitates rotation of the first spherical body 82 and, consequently,movement of the spherical body 82 and its corresponding two first guides84 along the corresponding first tracks. The spinning of the firstspherical body 82 advantageously facilitates removal of any scum thathas accumulated on the first spherical body 82 which would adverselyaffect sealing of the first valve 80.

In some embodiments, and as depicted in FIG. 6, a plurality of firstturbulators 400 may be coupled to and arranged about each of the twofirst guides 84. In some embodiments, the plurality of first turbulators400 may be a plurality of fins 420. The plurality of first turbulators400 aid in the rotation of the first spherical body 82 and thecorresponding two first guides 84 to facilitate improved movement alongthe corresponding first tracks due to the increased rotational velocityof the first spherical body 82. The increased rotational velocity alsofurther improves the removal of any scum that has accumulated on thefirst spherical body 82.

In some embodiments, and as depicted in FIGS. 5 and 6, the two firstguides 84 may be conical. In some embodiments, the two first guides 84may alternatively be shafts protruding from opposite ends of the firstspherical body 82, as illustrated in FIG. 7. In such an embodiment, theplurality of first turbulators 400 are disposed at a base of each shaft.Regardless of the shape of the two first guides 84, the two first guides84 may be formed as a unitary structure with the first spherical body 82or may be coupled to the first spherical body 82 adhesives, fixationelements, or the like.

FIG. 8 depicts a first sealing member for use in a valve assembly (e.g.,valve assembly 10) in accordance with some embodiments of the presentinvention. As illustrated in FIG. 8, in some embodiments, the firstsealing member may alternatively be a first disc 86 (i.e., cylindrical)having the two first guides 84 on opposite flat sides of the first disc86. In such an embodiment, the first opening 106 in the first valve seat100 may be a slot (as opposed to a hole) to form a seal with the firstdisc 86.

FIGS. 9 and 9A depict a valve assembly in accordance with someembodiments of the present invention. Specifically, FIGS. 9 and 9Adepict the valve assembly 10 incorporating the spherical body of FIG. 5.As shown in FIGS. 9 and 9A, in some embodiments, the valve assembly 10may include two first guide rails 50 and two second guide rails 52corresponding to the first and second valves 80, 115, respectively. Theends of two first guides 84 and two second guides 118 of the first andsecond spherical bodies 82, 116, respectively, are inserted into slotsformed in respective ones of the two first and second guide rails 50, 52to facilitate vertical movement of the first and second spherical bodies82, 116 between a closed position and an open position. For example,when the second pressure P2 is greater than the first pressure P1, thepressure difference forces the first valve 80 to open by pushing thefirst spherical body 82 upward along the two first guides 84. Inaddition, the air flow 180 rotates the spherical body 82 about an axispassing through the two first guides 84 as the first spherical body 82moves upwards, thus advantageously ridding the spherical body 82 ofaccumulated scum. As explained above, this rotation is further improvedand sped up by the incorporation of fins 420.

The two first and second guide rails 50, 52 may be separate elementscoupled to an inner wall of the housing 20 or may be formed with thehousing 20 as a unitary structure. In some embodiments, the two firstand second guide rails 50, 52 may alternatively be coupled or moldedwith the corresponding first and second valve seats 100, 110.

FIGS. 10 and 10A depict a valve assembly 10 in accordance with someembodiments of the present invention. As illustrated in FIGS. 10 and10A, in some embodiments, the housing 20 may be configured toaccommodate two first and second guide rails 50, 52 disposed at an angleA with respect to a plane in which each corresponding valve seat isdisposed. In some embodiments, the angle A may be between about 45° andabout 89°. Disposing the guard rails at an angle advantageously allowsfor the passage of more air flow 180 through the first and/or secondopenings 106, 112 because the first and second spherical bodies 82, 116are disposed outside of the air flow 180.

FIG. 11 depicts a cutaway view of a valve assembly in accordance withsome embodiments of the present invention. In some embodiments, and asdepicted in FIG. 11, the valve assembly 10 may include a first cage 700coupled to the first valve seat 100 about the first opening 106 and asecond cage 720 coupled to the second valve seat 110 about the secondopening 112. As depicted in FIG. 11, in some embodiments, the first andsecond cages 700, 720 are cylindrical and have an opening at one sidelarge enough to receive the first and second spherical bodies 82, 116,respectively, within the cages. The first and second cages 700, 720further include a plurality of openings disposed about and at the top ofeach cage to allow for the air flow 180 to pass through the cages. Thefirst and second cages 700, 720 are configured to limit the range ofmotion of the first and second spherical bodies 82, 116, respectively,to advantageously prevent the spherical bodies from moving aroundviolently in high flow applications (e.g., above about 20 pounds persquare inch (psi)). The first and second cages 700, 720 may be coupledto their respective valve seats or, alternatively, formed as one unitarystructure with their respective valve seats.

FIG. 12 depicts a cutaway view of a valve assembly 1200 in accordancewith some embodiments of the present invention. In some embodiments, andas depicted in FIG. 12, the valve assembly 1200 includes a housing 1202defining an interior volume 1265 and a first valve 1250 and a secondvalve 1255 disposed in the interior volume 1265. The first and secondvalves 1250, 1255 include first and second discs 1205, 1215,respectively, as sealing members. The first and second valves 1250, 1255further include first and second valve seats 1210, 1211, respectively,having first and second openings 1206, 1208, respectively. In such anembodiment, the first and second sealing members (i.e., the first andsecond discs 1205, 1215) have diameters that are larger than theirrespective first and second openings 1206, 1208. In some embodiments,the first and second valve seats 1210, 1211 may be formed of either oneof the rigid or compliant materials discussed above. Similar to theembodiments of valve assemblies discussed above, the valve assembly 1200may further include an inlet 1266, an outlet 1267, a first filterelement 1220 disposed at or proximate to the inlet 1266, and a secondfilter element 1240 disposed at or proximate to the outlet 1267.Although not described here for brevity, the valve assembly 1200 mayalso include elements in one or more of the embodiments of valveassemblies discussed above.

FIG. 12A depicts a perspective view of a bottom of the first disc 1205of the valve assembly depicted in FIG. 12. In some embodiments, thefirst disc 1205 may include a turbulator 1280. In some embodiments, theturbulator 1280 may include a plurality of fins 1282 extending from acentral body 1284 which is coupled to the bottom surface of the firstdisc 1205. In some embodiments, both the first and second discs 1205,1215 include turbulators 1280 to advantageously facilitate the removalof any scum that has accumulated on the discs by rotating the discs asair flows past the discs. It should be noted, however, that theturbulator 1980 may be embodied as an alternative structure that iscapable of rotating the discs as air flows past the discs.

In some embodiments, and as depicted in FIG. 12B, the first and seconddiscs 1205, 1215 may each include a plurality of alignment members 1250protruding radially outward from a peripheral edge of each of the firstand second discs, 1205, 1215. A circle circumscribing the plurality ofalignment members 1250 has a diameter less than an inner diameter of thehousing 1220 to ensure that each disc is correctly aligned above itscorresponding valve seat to provide a proper seal when abutting againstthe valve seat.

FIG. 13 depicts a cutaway view of a valve assembly 1300 in accordancewith some embodiments of the present invention. In some embodiments, andas depicted in FIG. 13, the first and second sealing members 1302, 1312may be shaped like an hourglass. The first sealing member 1302 includesa first upper hemispherical section 1304, a first lower hemisphericalsection 1306, and a first neck section 1308 connecting the first upperand lower hemispherical sections 1304, 1306. The first neck section 1308has a first diameter less than a first opening diameter of the firstopening 106 of the first valve seat 100. In order to provide a seal whenabutting against the first valve seat 100, a portion of each of thefirst upper and lower hemispherical sections 1304, 1306 is sized largerthan the first opening 106. Similarly, the second sealing member 1312includes a second upper hemispherical section 1314, a second lowerhemispherical section 1316, and a second neck section 1318 connectingthe second upper and lower hemispherical sections 1314, 1316. The secondneck section 1318 has a second diameter less than a second openingdiameter of the second opening 112 of the second valve seat 110. Inorder to provide a seal when abutting against the second valve seat 110,a portion of each of the second upper and lower hemispherical sections1314, 1316 is sized larger than the second opening 112.

In some embodiments, the first valve seat 100 may include a firstflexible membrane 1322 coupled to and disposed radially within a firstrigid ring 1324, which is coupled to an interior wall of the housing 20.In such an embodiment, the first opening 106 is formed in the firstflexible membrane 1322. The first flexible membrane 1322 may be formedof the compliant material discussed above and may have a shore hardnessbetween about 50 A and about 80 A and a vertical thickness between about0.5 mm and about 1.5 mm. The first rigid ring 1324 may be formed of therigid material discussed above. In some embodiments, the first valveseat 100 may alternatively be entirely formed of a rigid material.

In some embodiments, the second valve seat 110 may include a secondflexible membrane 1332 coupled to and disposed radially within a secondrigid ring 1334, which is coupled to an interior wall of the housing 20.In such an embodiment, the second opening 112 is formed in the secondflexible membrane 1332. The second flexible membrane 1332 may be formedof the compliant material discussed above and may have a shore hardnessbetween about 50 A and about 80 A and a vertical thickness between about0.5 mm and about 1.5 mm. The second rigid ring 1334 may be formed of therigid material discussed above. In some embodiments, the second valveseat 110 may alternatively be entirely formed of a rigid material. Insome embodiments, the first and second sealing members 1302, 1312 may beformed of the compliant material discussed above. In such an embodiment,the corresponding valve seats may be formed of either the compliant orrigid materials. In some embodiments, the first and second sealingmembers 1302, 1312 may alternatively be formed of the rigid materialdiscussed above. In such an embodiment, the corresponding valve seatsmay be formed of either the compliant or rigid materials. However, whenthe first and/or second sealing members 1302, 1312 and the correspondingvalve seat(s) are formed of the rigid material, the corresponding rigidvalve seat should include a compliant portion surrounding the opening(e.g., the collar 625 discussed above) to ensure a proper seal with therigid sealing member.

FIG. 14 depicts a valve assembly 1400 in accordance with someembodiments of the present invention. In some embodiments, and asdepicted in FIG. 14, at least one of a first sealing member 1482 and asecond sealing member 1483 of the first and second valves 80, 115,respectively, includes a central opening 1402, a non-permeable sac 1404coupled to and surrounding the central opening 1402, and a weightconfigured to stretch the non-permeable sac 1404 downwards and press thefirst and/or second sealing member 1482, 1483 against a correspondingfirst and/or second valve seat 100, 110. In some embodiments, the firstsealing member 1482 includes the central opening 1402, non-permeable sac1404, and the weight. In such an embodiment, and as depicted in FIG. 14,the second sealing member 1483 may be a disc, as described above withregards to FIG. 12.

In some embodiments, and as depicted in FIG. 14, the weight may be aball 1406 disposed within the non-permeable sac 1404. The ball 1406 hasa predetermined weight chosen open the corresponding valve when apredetermined pressure differential is achieved. In some embodiments,and as depicted in FIG. 14A, the non-permeable sac 1404 may include areduced diameter section 1408 having a diameter less than a width of theball 1406 and a pocket 1410 disposed beneath the reduced diametersection 1408 such that the ball 1406 is pushed beyond the reduceddiameter section 1408 into the pocket 1410. In some embodiments, and asdepicted in FIG. 15, the weight may alternatively be a disc 1506 that isattached to a lowermost portion of the non-permeable sac 1404.

FIG. 16 depicts a valve assembly in accordance with some embodiments ofthe present invention. In some embodiments, and as depicted in FIG. 16,a valve assembly 1600 includes a housing 1620 having an interior volume1665 and an inlet 1666 disposed at a first end 1699 of the housing 1620.The interior volume 1665 is fluidly coupled to an environmentsurrounding the valve assembly 1600 via the inlet 1666 and is defined byan interior wall 1622 and a ceiling 1640 disposed opposite the inlet1666 of the housing 1620. The valve assembly 1600 further includes apipe 1650 extending into the interior volume 1665 and having an end 1652disposed below the ceiling 1640 of the housing 1620. The pipe 1650 isfluidly coupled to an enclosed environment (not shown in FIG. 16) andincludes an inlet opening 1654 disposed in the end 1652.

The valve assembly 1600 includes a first valve 1680 and a second valve1690. In some embodiments, the first valve 1680 includes a first valveseat 1681 and a first sealing member 1682 disposed above the first valveseat 1681. The first valve seat 1681 may include a first seat outer ring1683 coupled to the interior wall 1622 and a first seat inner ring 1684coupled to an exterior wall of the pipe 1650. The first sealing member1682 includes a first central opening 1685, through which the pipe 1650extends and is moveable between an open position, in which air isallowed to flow through a first space 1686 between the first seat outerand inner rings 1683, 1684, and a closed position, in which the firstsealing member 1682 seals against the first valve seat 1681 to preventair from flowing through the first space 1686.

In some embodiments, the second valve 1690 includes a second valve seat1691 and a second sealing member 1692 disposed above the second valveseat 1691. The second valve seat 1691 may include a second seat outerring 1693 coupled to the interior wall 1622 and a second seat inner ring1694 coupled to an exterior wall of the pipe 1650. The second sealingmember 1692 includes a second central opening 1695, through which thepipe 1650 extends and is moveable between an open position, in which airis allowed to flow through a second space 1696 between the second seatouter and inner rings 1693, 1694, and a closed position, in which thesecond sealing member 1692 seals against the second valve seat 1691 toprevent air from flowing through the second space 1696. In someembodiments, at least one of the first and second sealing members 1682,1692 includes a plurality of turbulators 1980, as described with regardsto FIG. 12A, coupled to a lower surface of the corresponding sealingmember to spin sealing member when air flows past the plurality ofturbulators 1980.

In some embodiments, the pipe 1650 is coaxial with the housing 1620, thefirst valve 1680, and the second valve 1690. An annular filter element1610 may be disposed between the interior wall 1622 and the pipe 1650below the second valve seat 1691 at or proximate to the inlet 1666 toprevent contaminants from passing through the annular filter element1610 into the interior volume 1665. A second filter element 1611 may bedisposed within the pipe 1650 at or proximate the inlet opening 1654 toprevent contaminants from passing through the second filter element 1611into the pipe 1650 or from the pipe 1650 and into the interior volume1665.

In some embodiments, at least one of the first valve 1680 and the secondvalve 1690 (only the first valve 1680 in FIG. 16) may include a flexiblemembrane section 1630 disposed in the corresponding sealing member and aring 1632 disposed atop the flexible membrane section 1630. The ring1632 has a predetermined weight and is configured to bias thecorresponding sealing member towards the closed position. When thepressure beneath the valve seat is greater than the pressure above thevalve seat and the combined weight of the sealing member and the ring1632, the sealing member is moved to the open position. In someembodiments, and as depicted in FIG. 16, the flexible membrane section1630 may be an annular membrane 1670 having a circumference less than orequal to a circumference of the ring 1632. In some embodiments, and asdepicted in FIG. 16A, the flexible membrane section 1630 mayalternatively be a plurality of compliant support elements 1672 arrangesalong a circumference around the pipe 1650. The circumference of theplurality of compliant support elements 1672 is less than or equal tothe circumference of the ring.

FIGS. 17-20 depict exemplary enclosed environments in which theinventive valve assembly 10 may be used. As depicted in FIG. 17, thevalve assembly 10 is disposed in an enclosed environment 200 such as,for example, a pump pit. The pressure inside of the enclosed environmentis the pressure P1 in the valve assembly 10 because the first zone 40 isopen to the enclosed environment. In some embodiments, the enclosedenvironment 200 may include an enclosure 250, at least one conduit 210extending into the enclosure 250, a pump 220 disposed within theenclosure, and a pipe 224 coupled to an outlet of the pump 220 andextending out of the enclosure 250. The at least one conduit 210includes a first end 212 coupled to the inlet 66 of the valve assembly10 and a second end 214 disposed outside of the enclosure 250 in anambient environment. The pump 220 is configured to pump a medium 222(e.g., sewage or water) out of the enclosure 250. If, during operation,the pump 220 creates a vacuum in the interior volume of the enclosure250 (thus making P1 less than P2 and P3), the valve assembly 10functions as explained above to allow ambient air to flow from theambient environment, through the second end 214 of the at least oneconduit 210, through the valve assembly 10, and into the enclosure 250to alleviate the vacuum condition created by the pump 220. In someembodiments, the valve assembly 10 is configured to provide at leastabout 12 cubic inches per second for each millimeter of diameter of thepipe 224 when the valve assembly 10 is disposed in an enclosedenvironment in which a pump operates. Such an embodiment assumes thatthe pump 220 is a ⅓ horsepower pump.

Referring to FIG. 18, in some embodiments, the valve assembly 10 may bedisposed outside of the enclosed environment 200. For example, the firstend 212 of the at least one conduit 210 may be coupled to the enclosure250 and the second end 214 coupled to the outlet 67 of the valveassembly 10. As such, the flow path of ambient air into the enclosure250 is through the inlet 66, the outlet 67, and the at least one conduit210 and into the enclosure 250.

FIG. 19 depicts another embodiment of an enclosed environment in whichthe valve assembly 10 may be used. As illustrated in FIG. 19, the valveassembly 10 may be coupled to a piping system 300 coupled to, forexample, a sink drain. As explained above, such a piping system mayinclude a main pipeline 304 and a trap 302 coupled to the main pipeline304 and that provides a water seal preventing sewage gases from escapingfrom the main pipeline 304 into a building in which the sink isdisposed. To prevent a negative pressure downstream of the trap 302 frombreaking the water seal, the valve assembly 10 is coupled to a conduit1910, which is coupled to the main pipeline 304 via a t-connection. Insome embodiments, the conduit 1910 may include a first vertical portion1912, a u-shaped portion 1914, and a second vertical portion 1916disposed parallel to the first vertical portion 1912. The first verticalportion 1912 is coupled to the main pipeline 304 at a first end and tothe u-shaped portion 1914 at a second end opposite the first end. Thesecond vertical portion 1916 is coupled to an end of the u-shapedportion 1914 opposite the first vertical portion 1912. The valveassembly 10 is coupled to the second vertical portion 1916 at an endopposite the u-shaped portion 1914. In such an embodiment, the pressureinside of the main pipeline 304 is the first pressure P1 and the ambientpressure in the surrounding environment is the third pressure P3. Theair admittance requirement for the flow 180 into the piping system 300is generally about 1 cubic feet per minute or about 0.47 litter persecond, but these values may vary based on the scale/size of the pipingsystem 300.

FIG. 20 depicts an embodiment of an enclosed environment in which thevalve assembly 10 may be incorporated. As illustrated in FIG. 20, thevalve assembly 10 is coupled in-line with the piping system 300. Thatis, a first section 310 of the piping system 300 is coupled to the inlet66 and a second section 320 of the piping system 300 is coupled to theoutlet 67 such that the first zone 40 is fluidly coupled to the secondsection 320 and the third zone 60 is fluidly coupled to the firstsection 310. In this configuration, flow 180 is allowed to move from thefirst section 310 to the second section 320, but not from the secondsection 320 to the first section 310, thus advantageously avoidingbackflow.

FIG. 21 depicts a cross-sectional view of the conduit 1910 and the valveassembly in accordance with some embodiments of the present invention.In some embodiments, the conduit 1910 may include a flexible membrane2100 disposed in within an upper section of the u-shaped portion 1914perpendicular to a plane of the first vertical portion 1912. Theflexible membrane 2100 may be coupled to an interior wall 2122 of theu-shaped portion 1914 so that an upper volume 2102 above the flexiblemembrane 2100 is fluidly isolated from a lower volume 2103 below theflexible membrane 2100. The flexible membrane 2100 advantageouslyprovides a countermeasure against backpressure resulting from increasedpressure in the main pipeline 304 (not shown in FIG. 21). When such abackpressure exists, the first and/or second valves 80, 115 may beforced even further into a closed position, thus possibly damaging thevalves or resulting in one or both of the valves being stuck in a closedposition. The flexible membrane 2100 alleviates the increase in pressureby expanding upwards to temporarily increase the volume of the lowervolume 2103, thus alleviating some or all of the backpressure andavoiding damage to the valves. In some embodiments, a hole 2104 may beformed in the top of the u-shaped portion 1914 so that air within theupper volume 2102 has an escape when the flexible membrane 2100 expandsupwards. In some embodiments, there is no hole above the flexiblemembrane 2100. Instead, the upper volume 2102 may contain an ideal gas,which is lighter than air and occupies less space/volume, thus allowingfor the expansion of the flexible membrane 2100 in a sealed environment.

FIGS. 22-23A depict schematic views of a pressure-monitoring device 500for use with a valve assembly in accordance with some embodiments of thepresent invention. In some embodiments, the pressure-monitoring device500 may be coupled to the housing 20 to monitor the second pressure P2in the second zone 45 to allow for inspection of the valve assembly 10and determination of whether or not a leak in one of the first andsecond valves 80, 115 exists. In some embodiments, thepressure-monitoring device 500 may include a piston 520 disposed withina housing 515. An indicator rod 510 may be coupled to the piston 520 ona side opposite the inner volume of the housing 515 to provide anindication of the second pressure P2 within the second zone 45. In someembodiments, the pressure-monitoring device 500 may also include asignal transmitter 530 which is configured to detect the position of thepiston 520 and transmit a pressure reading based on the detectedposition to a remote device (e.g., a computer, a cellular phone, etc.).As the second pressure P2 in the second zone 45 increases, the positionof the piston 520 is raised. Although a specific pressure-monitoringdevice 500 has been described, it should be noted that anypressure-monitoring device capable of measuring pressure within thevalve assembly 10.

What claimed is:
 1. A valve assembly to allow or stop a flow for usewith an enclosed environment, comprising: (a) a housing having aninterior volume, an inlet disposed at a first end of the housing andfluidly coupled to an environment surrounding the housing, and an outletdisposed at a second end of the housing, wherein said interior volume isdivided into a first zone, a second zone, a third zone, wherein saidfirst zone occupies a predetermined volume of said interior volumeproximate said outlet, wherein said third zone occupies a predeterminedvolume of said interior volume proximate said inlet, wherein said secondzone occupies a predetermined volume of said interior volume betweensaid first zone and said third zone, wherein a first zone pressureexists in said first zone, wherein a second zone pressure exists in saidsecond zone, and wherein a third zone pressure exists in said thirdzone; (b) a first valve inside said housing, comprising a first valveseat, wherein said first valve seat is disposed between said first zoneand said second zone wherein said first valve seat has a first opening,wherein said first valve further comprises a first sealing member,wherein said first sealing member has a dimension greater than saidfirst opening, wherein said first sealing member dimension is less thanthe inner diameter of said housing, wherein said first sealing memberhas a predetermined weight, and wherein said first sealing member canmove inside said first zone and away from said first valve seat, whereinsaid first valve is in an open position when said second zone pressureis greater than said sealing member predetermined weight and said firstzone pressure, and wherein said first valve is in a closed position whensaid second zone pressure is less than said sealing member predeterminedweight and said first zone pressure; (c) a second valve inside saidhousing, comprising a second valve seat, wherein said second valve seatis disposed between said second zone and said third zone wherein saidsecond valve seat has a second opening, wherein said second valvefurther comprises a second sealing member, wherein said second sealingmember has a dimension greater than said second opening, wherein saidsecond sealing member dimension is less than the inner diameter of saidhousing, wherein said second sealing member has a predetermined weight,and wherein said second sealing member can move inside said second zoneand away from said second valve seat, wherein said second valve is in anopen position when said third zone pressure is greater than said sealingmember predetermined weight and said second zone pressure, and whereinsaid second valve is in a closed position when said third zone pressureis less than said sealing member predetermined weight and greater thansaid second zone pressure; (d) a flexible membrane disposed in saidfirst zone, wherein said flexible membrane is coupled to said interiorwall in said first zone, wherein said flexible membrane has an isolatedvolume from said interior volume, wherein a pressure exists in saidisolated volume of said flexible membrane, wherein said flexiblemembrane can expand to increase said first zone volume when said firstzone pressure is greater than said isolated volume pressure of saidflexible membrane and wherein said flexible membrane can expand todecrease said first zone volume when said first zone pressure is lessthan said isolated volume pressure of said flexible membrane.
 2. Thevalve assembly of claim 1, further comprising a pressure indicator,wherein said pressure indicator is responsive to said middle flowpassage pressure, wherein said pressure indicator is visible on anexternal surface of said housing, and wherein said pressure indicatorshows a pressure status of said middle flow passage pressure.
 3. Thevalve assembly of claim 2, further comprising a signal transmitter totransmit said pressure status of said pressure indicator.
 4. The valveassembly of claim 1, wherein said isolated volume of said flexiblemembrane is filled with a predetermined amount of ideal gas.
 5. Thevalve assembly of claim 1, wherein a hole is formed in said housing,wherein said hole communicates said isolated volume of said flexiblemembrane and said environment surrounding said housing.
 6. The valveassembly of claim 5, further comprising a pressure indicator, whereinsaid pressure indicator is responsive to said middle flow passagepressure, wherein said pressure indicator is visible on an externalsurface of said housing, and wherein said pressure indicator shows apressure status of said middle flow passage pressure.
 7. The valveassembly of claim 6, further comprising a signal transmitter to transmitsaid pressure status of said pressure indicator.
 8. A valve assembly toallow or stop a flow for use with an enclosed environment, comprising: ahousing having an interior volume, an inlet disposed at a first end ofthe housing and fluidly coupled to an environment surrounding thehousing, wherein said interior volume is defined by a wall and a ceilingof the housing, and wherein said ceiling is disposed at a second end ofthe housing, wherein said interior volume is divided into a first zone,a second zone and a third zone, wherein a force exists in said firstzone, wherein a force exists in said second zone, and wherein a forceexists in said third zone; a pipe extending proximate the housing inletcoaxial with the housing into the housing interior volume and having apipe end disposed above the housing inlet and below the ceiling of thehousing, wherein the end of the pipe has an inlet opening fluidlycoupled to the housing interior volume; a first valve comprising a firstvalve seat and a first sealing member, wherein said first valve seatdivides said first zone and said second zone, wherein said first valveseat is coupled to said wall of said housing and said exterior wall ofsaid pipe, wherein said first valve seat has a first opening, whereinsaid first sealing member has a dimension greater than said first valveseat opening, wherein said first sealing member dimensions are less thansaid wall of said housing and said exterior wall of said pipe, whereinsaid first sealing member is dimensioned above said first valve seat,and wherein said first sealing member is urged between an open positionin which said force that exists in said first zone is less than saidforce that exists in said second zone urging said first sealing memberto said open position allowing a flow to pass through said first valveseat opening from said second zone to said first zone and a closedposition in which said force that exists in said first zone is greaterthan said force that exists in said second zone urging said firstsealing member to said closed position preventing flow to pass throughsaid first valve seat opening from said first zone to said second zone;a second valve comprising a second valve seat and a second sealingmember, wherein said second valve seat divides said second zone and saidthird zone, wherein said second valve seat is coupled to said wall ofsaid housing and said exterior wall of said pipe, wherein said secondvalve seat has a second opening, wherein said second sealing member hasa dimension greater than said second valve seat opening, wherein saidsecond sealing member dimensions are less than said wall of said housingand said exterior wall of said pipe, wherein said second sealing memberis dimensioned above said second valve seat, and wherein said secondsealing member is urged between an open position in which said forcethat exists in said second zone is less than said force that exists insaid third zone urging said second sealing member to said open positionallowing a flow to pass through said second valve seat opening from saidthird zone to said second zone and a closed position in which said forcethat exists in said second zone is greater than said force that existsin said third zone urging said second sealing member to said closedposition preventing flow to pass through said second valve seat openingfrom said second zone to said third zone.
 9. The valve assembly of claim8, further comprising a indicator, wherein said indicator is responsiveto said force in said second zone, wherein said indicator is visible onan external surface of said housing, and wherein said indicator shows astatus of said force in said second zone.
 10. The valve assembly ofclaim 9, further comprising a signal transmitter to transmit saidindicator status of said indicator.
 11. The valve assembly of claim 8,further comprising a flexible membrane disposed in said first zone,wherein said flexible membrane is coupled to said interior wall in saidfirst zone, wherein said flexible membrane has an isolated volume fromsaid interior volume, wherein a pressure exists in said isolated volumeof said flexible membrane, wherein said flexible membrane can expand toincrease said first zone volume when said first zone force is greaterthan said isolated volume pressure of said flexible membrane and whereinsaid flexible membrane can expand to decrease said first zone volumewhen said first zone force is less than said isolated volume pressure ofsaid flexible membrane.
 12. The valve assembly of claim 11, wherein saidisolated volume of said flexible membrane is filled with a predeterminedamount of ideal gas.
 13. The valve assembly of claim 11, wherein a holeis formed in said housing, wherein said hole communicates said isolatedvolume of said flexible membrane and said environment surrounding saidhousing.
 14. The valve assembly of claim 11, further comprising aindicator, wherein said indicator is responsive to said force in saidsecond zone, wherein said indicator is visible on an external surface ofsaid housing, and wherein said indicator shows a status of said force insaid second zone.
 15. The valve assembly of claim 14, further comprisinga signal transmitter to transmit said indicator status of saidindicator.